Currently, an overwhelming majority of smartphones already have a video shooting function. Because limitations are imposed on lenses and costs, the luminous flux on a single pixel is relatively small. Particularly, in an indoor scenario in which illumination is insufficient or illuminance is low, exposure of some mobile phones is insufficient to cause an obviously dark video, and use of a video call is limited. By means of video enhancement processing, a video effect in this type of scenario may be effectively improved, so as to improve a subjective feeling of a customer, thereby expanding a video call application scenario.
A conventional video enhancement technology mainly uses image enhancement for reference. For example, in a histogram equalization manner, an enhancement curve is a cumulative probability distribution function of an image, and can stretch the contrast of the entire image to a maximum extent. Because a histogram of an image in a dark scenario has a peak, the image is excessively enhanced after histogram equalization processing, and consequently the image is distorted.